If you are in a lot of pain from an injury, surgery, or a long-term illness then buy Methadone 5 mg online and get relief from major pain. Methadone also blocks the high from drugs like codeine, heroin, hydrocodone, morphine, and oxycodone. Side effects: Nausea, vomiting, constipation, lightheadedness, dizziness, dry mouth, drowsiness, or sweating may occur.